Explanation
Scope is the important factor that the BA needs to understand to ensure the workshop remains focused on the topic in question. Scope is the boundary or extent of the business analysis effort, which defines what is included and excluded from the change initiative. Scope also provides the context and direction for the requirements elicitation and analysis activities. By understanding the scope, the BA can plan and facilitate the workshop effectively, and avoid any irrelevant, out-of-scope, or conflicting discussions or issues. The other options are not the best answers, as they are not as critical as scope for keeping the workshop focused, although they may be related to the topic in question. For example, future state is the desired outcome of the change initiative, assets are the resources or capabilities of the enterprise, and risk register is the document that records the identified risks and their responses. References: CBAP Handbook, CBAP Study Guide, BABOK Guide